What Is the MAX6675? K-Type Thermocouple Reader and Uses
The MAX6675 is a temperature converter that reads a K-type thermocouple (SPI). It amplifies the thermocouple voltage, converts it to 12-bit digital and does cold-junction compensation; it measures 0–1024 °C (0.25 °C) — for high temperatures like ovens/reflow/extruders. It is for K-type only; connect the thermocouple polarity correctly.
The MAX6675 is a temperature converter that reads a K-type thermocouple (SPI). It amplifies the very small voltage a thermocouple produces, converts it to 12-bit digital and does cold-junction compensation; it is a standard chip for high-temperature measurement. For the concept, see what is a temperature sensor.
What is the MAX6675 used for?
Ovens, reflow, extruders and high-temperature (0–1024 °C) measurement — far above the range of sensors like the DS18B20/LM35. It connects to an MCU over SPI; it requires a K-type thermocouple.
Specifications
| Parameter | Value |
|---|---|
| Input | K-type thermocouple |
| Range | 0–1024 °C (0.25 °C resolution) |
| Interface | SPI (read-only) |
| Extra | Cold-junction compensation (internal) |
Watch out
The thermocouple polarity must be connected correctly (reversed, the value goes the wrong way). The MAX6675 is for K-type only; other thermocouple types need a different chip (e.g. the MAX31855). Read-only (no write); one-way SPI.
Equivalents
- MAX31855: wider range, negative temperatures, different thermocouple types.
- MAX31856: a multi-type thermocouple interface.
- DS18B20: for low temperature (−55…+125 °C).
Find it in our catalog
Use the MAX6675 search.